For many years manufacture of cement and the like has preferentially taken place in kiln plant including a rotary kiln allowing for, compared with shaft kilns, a continuous treatment of raw materials fed to the plant. The development of such rotary kiln plant has through recent times undergone a change towards reducing the size of the mechanically rather complicated kiln construction by arranging some of the previous functions of the rotary kiln to take place in stationary parts of the plant such as separate preheating and precalcining installations. Such plants are known for example from British Patent Specifications Nos. 1,108,589, 1,434,091 and 1,428,828 according to which the rotary kiln carries out two functions in addition to the transport function of treated materials, namely heating from about 900.degree. C. to the reaction temperature in the kiln of the material precalcined in the precalcination zone, and providing retention time in the kiln for the reacting material under treatment.
The next logical step in this development is to move the heating function from the rotary kiln out into a separate, stationary installation thereby making it possible to further reduce the functions of the rotating plant installation. This reduction is desirable due to smaller overall construction costs and a better running or operating economy of the plant. A plant of this type is known from German OLS No. 2,846,584. However, the problem of moving the heating function to a stationary installation may be encumbered by the melting of as much as 20% of the material. Such melting may cause the charge to stick and clog and therefore render the charge difficult to handle during further treatment in the plant.
I have invented a method and a kiln plant where the heating of the treated material to its reaction temperature takes place in a stationary burning installation and where the above mentioned problem concerning transportation of treated material in the plant has been solved.